@@ -6,7 +6,7 @@
@c %**end of header
@copying
-Copyright @copyright{} 2010, 2011 Free Software Foundation, Inc.
+Copyright @copyright{} 2010-2013 Free Software Foundation, Inc.
@quotation
Permission is granted to copy, distribute and/or modify this document
@@ -123,8 +123,8 @@ The following mathematical constants of
@item @code{M_LN2q}: natural logarithm of 2
@item @code{M_LN10q}: natural logarithm of 10
@item @code{M_PIq}: pi
-@item @code{M_PI_2q}: two pi
-@item @code{M_PI_4q}: four pi
+@item @code{M_PI_2q}: pi divided by two
+@item @code{M_PI_4q}: pi divided by four
@item @code{M_1_PIq}: one over pi
@item @code{M_2_PIq}: one over two pi
@item @code{M_2_SQRTPIq}: two over square root of pi